Topband: Shunt feeding the Skyneedle - new developments

[Tom W8JI]

The j11 ohms is the best I can get period. I was able to get j0 when the cap 
was outside of the steel enclosure with a better bandwidth. Maybe I should 
throw my $400 enclosure and find a fibergla$$ enclosure. But as others have 
indicated I should probably just live with it.>>>

1.) How do you know the system really has some reactance?

2.) What is the SWR, that is more accurate.

3.) The SWR is meaningless anyway for control settings when  it is below 
maybe 1.3, and is typically meaningless for system losses when below 4.0:1 
for short cables on 160 meters. A 40 j10 load (if it is that) is around 
1.3:1, so it falls in the meaningless category


Do you think a smaller (physically) vacuum cap would have less interaction 
with the steel enclosure.  The one I have is only 3" round and 6" long. The 
air variable I'm using is 13" long and 7" round at mesh>>>>

RF behavior with chassis and cabinets and wiring can be complicated. Some 
people who work around it all their life never actually get a feel for how 
simple systems work, let alone things that might get colex like high 
impedance lines and physically large components inside close spaced boxes.

The interaction depends on the circuit impedance and the impedance of any 
components and wiring at various points in the system inside the box. You'll 
probably never get a meaningful answer because the problem is small, an 
answer requires knowing the actual impedances of everything, and at a 
minimum a feel for how the box and wiring *you* have interacts with the 
impedances.

The important thing at this point is how the equipment in the shack behaves 
with what you have, because any actual losses are meaningless.

73 Tom